fA cyclone warning has been issued for coastal areas of Western Australia, with Bureau of Meteorology forecasters expecting a tropical low off the coast of Broome to strengthen over the weekend into a category 3 storm.

Heavy rain and gusts of up to 100 kilometres per hour are expected to hit the WA coast between Kuri Bay and Broome this afternoon, and further extend to De Grey north of Port Hedland by Sunday morning.

Forecaster Joe Courtney says the storm - currently a tropical low situated about 430 kilometres north of Broome - is slow moving but expected to intensify as it approaches the coast, developing into a "significant" cyclone that could make landfall on Tuesday.